If you overheated the engine, the damage could be substantial. And there is a question of why the radiator cracked - lots of possibilities including a leaking/failed head gasket causing over-pressurization.

Without considering any of that, the actual radiator cost isn't too bad.

The Behr version of that radiator (I have installed it without problem) is available for about $210 online. A couple gallons of BMW coolant is another $50. Not a bad DIY, but probably 2 hours for a shop to replace and refill it if you are paying someone. Depending on where you are on your mileage and maintenance, may be a good time to replace some radiator hoses, thermostat, etc. which will increase parts cost.

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David.X5
2001 X5 4.4i Sport
SOLD! at 160k miles